CHROMOSOMAL ABNORMALITIES IN LEUKEMIA IN IRAN: A PILOT STUDY

Objective-To carry out cytogenetics investigations on bone marrow and peripheral blood samples obtained from patients with leukemia. Methods-A total of 35 bone marrow or blood samples from all types of leukemia patients was referred to the Cytogenetic Laboratory of Tehran University of Medical Sciences. The referral centers were the Hematology and Oncology Centers in Shariati Hospital and the Children’s Medical Center. Cell culturing including high resolution (HR) and Giemsa banding (G-bands by trypsin using Giemsa strain; GTG) were carried out according to standard protocols. Chromosome analysis was performed following international system for human cytogenetics nomenclature (ISCN) guidelines (1995). Results-Among the 28 cases, chromosomal abnormality rate was 50% in acute myelogenous leukemia (AML), 80% in acute lymphocytic leukemia (ALL), 83% in chronic myelocytic leukemia (CML) and 100% in the Lymphoproliferative disease (LPD) groups. Two patients in the myeloproliferative disease (MPD)/CML group had normal karyotype and were therefore treated as MPD. The types of observed chromosomal abnormality were translocation 15/17 in AML-M3 patients, double trisomy 8 and 13 in an AML patient, hyperdiploidy of 50- 55 of chromosomes in a child with ALL, a double abnormality of Philadelphia and t 7/8 in a CML patient at blast stage and a complex variant Philadelphia translocation of a t4/9/22 in a CML patient. Conclusion-Despite being a pilot study with a small number of samples, the majority of patients demonstrated chromosomal abnormalities comparable to previously reported cases in other countries. The type of chromosomal abnormality was relevant to diagnosis and stage of the disease.